<?php
/*
 *  $Id: Creditcard.php 7490 2010-03-29 19:53:27Z jwage $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

/**
 * Doctrine_Validator_Creditcard
 *
 * @package     Doctrine
 * @subpackage  Validator
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        www.doctrine-project.org
 * @since       1.0
 * @version     $Revision: 7490 $
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 */
class Doctrine_Validator_Creditcard extends Doctrine_Validator_Driver
{
	/**
	 * checks if given value is a valid credit card number
	 *
	 * @link http://www.owasp.org/index.php/OWASP_Validation_Regex_Repository
	 * @param mixed $value
	 * @return boolean
	 */
	public function validate($value)
	{
		if (is_null($value)) {
			return true;
		}
		$cardType = "";
		$card_regexes = array(
            "/^4\d{12}(\d\d\d){0,1}$/"      => 'visa',
            "/^5[12345]\d{14}$/"            => 'mastercard',
            "/^3[47]\d{13}$/"               => 'amex',
            "/^6011\d{12}$/"                => 'discover',
            "/^30[012345]\d{11}$/"          => 'diners',
            "/^3[68]\d{12}$/"               => 'diners',
		);
		foreach ($card_regexes as $regex => $type) {
			if (preg_match($regex, $value)) {
				$cardType = $type;
				break;
			}
		}
		if ( ! $cardType) {
			return false;
		}
		/* mod 10 checksum algorithm */
		$revcode = strrev($value);
		$checksum = 0;
		for ($i = 0; $i < strlen($revcode); $i++) {
			$currentNum = intval($revcode[$i]);
			if ($i & 1) {               /* Odd position */
				$currentNum *= 2;
			}
			/* Split digits and add. */
			$checksum += $currentNum % 10;
			if ($currentNum > 9) {
				$checksum += 1;
			}
		}
		if ($checksum % 10 == 0) {
			return true;
		} else {
			return false;
		}
	}
}